A composition is described having improved oral permeability of polar agents such as neuraminidase inhibitors. The composition includes one or more polar agents and one or more permeability enhancers such that the composition increases the amount of the polar agent capable of being transported across a Caco-2 cell membrane by at least 150% relative to the amount capable of being transported across the Caco-2 Cell membrane in the absence of the permeability enhancer. Oral dosage forms including the composition, and methods of treating or preventing influenza infection are also provided.
